The localization of proteins and MRNAS in animal and human cells and tissues are crucial to our understanding the neuroendocrine and metabolic regulation of the menstrual cycle. Five of the six Units in the Center will examine protein and MRNA distributions to answer key questions regarding hormonal expression, regulation, and site of action. Core C, the histology, immunohistochemistry, and in situ hybridization Core, directed by Dr. Roberts, will centralize these functions in a well equipped laboratory run by experienced personnel. This will optimize and standardize the quality of the results, eliminate the development and perfection of these techniques by the individual Units, and greatly cut material and personnel expenses.